Nancy Klein

School-age outcomes in children with birth weights under 750 g.

Background Since the mid-1980s, increasing numbers of children with birth weights under 750 g have survived to school age. Methods We matched a regional cohort of 68 surviving children born from 1982 through 1986 with birth weights under 750 g (mean, 670 g; gestational age, 25.7 weeks) with 65 children weighing 750 to 1499 g at birth and 61 children born at term. Growth, neurosensory status, and functioning at school age in the three groups were compared. Associations of biologic and social risk factors with major developmental outcomes were examined by means of logistic-regression analyses. Results Children with birth weights under 750 g were inferior to both comparison groups in cognitive ability, psychomotor skills, and academic achievement. They had poorer social skills and adaptive behavior and more behavioral and attention problems. The mean (±SD) Mental Processing Composite score for the cohort was 87 ±15, as compared with 93 ±14 for children with birth weights of 750 to 1499 g and 100 ±13 for chil...

Poor predictive validity of the Bayley Scales of Infant Development for cognitive function of extremely low birth weight children at school age.

Objective. The Bayley Scales of Infant Development, Second Edition (BSID II) are commonly used to assess outcomes of extremely low birth weight (ELBW) infants. We sought to assess the predictive validity of the BSID II Mental Developmental Index (MDI) for cognitive function at school age. Design/Methods. Of 330 ELBW infants admitted in 1992–1995, 238 (72%) survived to the age of 8 years, of whom 200 (84%) were tested at both 20 months’ corrected age (CA) and 8 years. Mean birth weight was 811 g, mean gestational age was 26.4 weeks, 41% were boys, and 60% were black. Measures included the BSID II at 20 months’ CA and the Kaufman Assessment Battery for Children (KABC) Mental Processing Composite (MPC) at 8 years’ postnatal age. BSID II MDI and MPC scores were compared and the predictive validity calculated for all 200 ELBW children and for the 154 ELBW neurosensory-intact subgroup. Predictors of stability or change in cognitive scores were examined via logistic regression adjusting for gender and sociodemographic status. Results. For all ELBW children, the mean MDI was 75.6 ± 16 versus a mean KABC of 87.8 ± 19. For the neurosensory-intact subgroup, the mean MDI was 79.3 ± 16 and the mean KABC was 92.3 ± 15. Rates of cognitive impairment, defined as an MDI or KABC of <70, dropped from 39% at 20 months’ CA to 16% at 8 years for the total ELBW population and from 29% to 7% for the neurosensory-intact subgroup. The positive predictive value of having an MPC of <70 given an MDI of <70 was 0.37 (95% confidence interval [CI]: 0.27, 0.49) for all ELBW infants, 0.20 (95% CI: 0.10, 0.35) for the neurosensory-intact subgroup, and 0.61 (95% CI: 0.42, 0.77) for the neurosensory-impaired subgroup. The negative predictive values were 0.98, 0.99, and 0.85 for the 3 groups, respectively. Neurosensory impairment at 20 months’ CA predicted lack of improvement of cognitive function (odds ratio: 6.9; 95% CI: 2.4, 20.2). Children whose cognitive scores improved between 20 months and 8 years had significantly better school performance than those whose scores stayed at <70, but they did less well than those whose scores were persistently >70. Conclusions. The predictive validity of a subnormal MDI for cognitive function at school age is poor but better for ELBW children who have neurosensory impairments. We are concerned that decisions to provide intensive care for ELBW infants in the delivery room might be biased by reported high rates of cognitive impairments based on the use and presumptive validity of the BSID II MDI.

Effect of Very Low Birth Weight and Subnormal Head Size on Cognitive Abilities at School Age

BACKGROUND We tested the hypothesis that very-low-birth-weight (less than 1.5 kg) infants with perinatal growth failure whose head size is not normal by eight months of age (corrected for prematurity) have significantly poorer growth and neurocognitive abilities at school age than very-low-birth-weight children with a normal head size at eight months. We also hypothesized that these differences would persist even after control for major neurologic impairment and perinatal and sociodemographic risk factors. METHODS We have followed a cohort of very-low-birth-weight children since their birth during the period 1977 to 1979. At eight to nine years of age 249 children were evaluated with a neurologic examination and tests of intelligence; receptive and expressive language skills; speech, reading, mathematics, and spelling aptitude; visual and fine motor abilities; and behavior. Ages were corrected for premature birth. RESULTS Among these 249 very-low-birth-weight children, head size was subnormal (less than the mean -2 SD for age) at birth in 30 (12 percent), at term in 57 (23 percent), and at eight months in 33 (13 percent). As compared with the 216 children with normal head sizes, the 33 children with subnormal head sizes at the age of eight months had significantly lower mean birth weights (1.1 vs. 1.2 kg) and higher neonatal risk scores (71 vs. 53) and at the age of eight years had a higher incidence of neurologic impairment (21 percent vs. 8 percent) and lower IQ scores (mean verbal, 84 vs. 98). Even among the children without neurologic abnormalities, a subnormal head size at eight months of age was predictive of poorer verbal and performance IQ scores at eight years of age; lower scores for receptive language, speech, reading, mathematics, and spelling; and a higher incidence of hyperactivity. In multiple regression analyses to control for socioeconomic and neonatal risk factors, intrauterine growth failure, birth weight, and neurologic impairment, a subnormal head size at eight months of age had an independently adverse effect on IQ and on scores for receptive language, speech, reading, and spelling. CONCLUSIONS In very-low-birth-weight infants, perinatal growth failure, as evidenced by a subnormal head circumference at eight months of age, is associated with poor cognitive function, academic achievement, and behavior at eight years of age.

Behavioral outcomes and evidence of psychopathology among very low birth weight infants at age 20 years.

Objective. Information on the mental health of very low birth weight (VLBW; <1500 g) children in young adulthood is sparse. We thus sought to examine gender-specific behavioral outcomes and evidence of psychopathology in a cohort of VLBW young adults at 20 years of age. Methods. We compared a cohort of 241 survivors among VLBW infants who were born between 1977 and 1979 (mean birth weight: 1180 g; mean gestational age at birth: 29.7 weeks), 116 of whom were men and 125 of whom were women, with 233 control subjects from the same population in Cleveland who had normal birth weights (108 men and 124 women). Young adult behavior was assessed at 20 years of age with the Achenbach Young Adult Self-Report and the Young Adult Behavior Checklist for parents. In addition, the young adults and parents completed the ADHD Rating Scale for Adults. Gender-specific outcomes were adjusted for sociodemographic status. Results. VLBW men reported having significantly fewer delinquent behaviors than normal birth weight (NBW) control subjects, but there were no differences on the Internalizing, Externalizing, or Total Problem Behavior scales. Parents of VLBW men reported significantly more thought problems for their sons than did parents of control subjects. VLBW women reported significantly more withdrawn behaviors and fewer delinquent behavior problems than control subjects. Their rates of internalizing behaviors (which includes anxious/depressed and withdrawn behaviors) above the borderline clinical cutoff were 30% versus 16% (odds ratio: 2.2; 95% confidence interval [CI]: 1.2-4.1). Parents of VLBW women reported significantly higher scores for their daughters on the anxious/depressed, withdrawn, and attention problem subscales compared with control parents. The odds ratios for parent-reported rates above the borderline-clinical cutoff among women for the anxious/depressed subscale was 4.4 (95% CI: 1.4-13.5), for thought problems was 3.7 (95% CI: 1.2-11.6), and for attention problems was 2.4 (95% CI: 1.0-5.5). There were no differences in the young adult self-report of attention-deficit/hyperactivity disorder (ADHD). Parents of VLBW men reported higher mean scores on the attention subtype of ADHD but not higher rates of ADHD. Conclusion. The increase in psychopathology among VLBW survivors in young adulthood indicates a need for anticipatory guidance and early intervention that might help to prevent or ameliorate potential psychopathology.

Middle-School-Age Outcomes in Children with Very Low Birthweight

Most previous studies of children with birthweight <750 g have focused on early childhood sequelae. To evaluate later outcomes, a regional sample of 60 <750-g birthweight children was compared at middle school age (M = 11 years) to 55 children with birthweight 750-1,499 g and 49 term controls. The groups were matched on age, gender, and demographic variables at the time of an early-school-age assessment (mean age 7 years). The <750-g birthweight group fared less well at middle school age than the term group on measures of cognitive function, achievement, behavior, and academic performance. In many instances, outcomes were less favorable for the <750-g children than for the 750 to 1,499-g group. Children in the <750-g group who were free of neurosensory disorders and global cognitive impairment performed more poorly on several tests than their term counterparts. Group differences in this subsample on tests of motor skills, math, and the ability to copy and recall a complex drawing remained significant even after controlling for IQ. Disparities between the <750-g and term groups increased with age for some measures. Despite favorable outcomes for many children in the <750-g group, this population is at risk for long-term developmental problems.

The Effect of Very Low Birth Weight and Social Risk on Neurocognitive Abilities at School Age

We tested the hypothesis that very low birth weight (VLBW > 1.5 kg) children would have significantly poorer neurocognitive abilities at school age than would normal birth weight full-term age mates, that differences would persist after control for neurologic impairment and social risk, and that VLBW would interact with social risk. Two hundred forty-nine VLBW children and a randomly selected sample of 363 normal birth weight age mates born 1977 through 1979 were tested at 8 years. A neurologic examination and tests of intelligence, language, speech, reading, mathematics, spelling, visual and fine motor abilities, and behavior were performed. Twenty-four (10%) VLBW had a major neurologic abnormality compared with none of the controls. VLBW had significantly poorer scores on all tests, with the exception of speech and the total behavior score. These differences persisted among VLBW children without major neurologic abnormality, with the exception of social competence, reading, and spelling. Even normal IQ, neurologically normal VLBW had significantly poorer scores than did controls in expressive language, memory, visuomotor, and fine motor function, and measures of hyperactivity. When social risk was controlled in multiple regression analyses, VLBW still had an adverse effect on all outcome measures with the exception of speech. Social risk was, however, the major determinant of outcome. We found an interaction between VLBW and social risk only in verbal IQ and in the opposite direction than hypothesized.

Children who were very low birth weight: development and academic achievement at nine years of age.

Children born at very low birth weights (VLBW) (≤1500 g) who were beneficiaries of modern neonatal intensive care are reaching middle childhood, and their school achievement can be evaluated. We compared 65 9-year-old children born in 1976, who were very low birth weight and who were free of neurological impairment, with 65 children of normal birth weight who had been matched for race, sex, age, and social class on measures of IQ, cognitive, visuo-motor, and fine motor abilities, and academic achievement. VLBW children scored significantly lower than controls on the WISC-R, Bender-Gestalt, Purdue Pegboard, subtests from the Woodcock Johnson Cognitive Abilities Battery, and reading and mathematics (math) achievement. Exploratory analysis of a subset of 43 VLBW and matched controls with IQ scores ≤85 yielded a similar trend, except that, on achievement tests, differences were significant only in math. Further analyses revealed that the differential in math achievement between VLBW and control children is not fully attributable to differences in IQ.

Behavioral Outcomes of Extremely Low Birth Weight Children at Age 8 Years

Objective: To describe the prevalence of behavioral problems and symptomatology suggestive of Autism and Aspergers disorders at age 8 years among extremely low birth weight (ELBW, <1 kg) children, born 1992 through 1995. Method: Parent reports of the behavior of 219 ELBW (mean birth weight, 810 g; gestational age 26 weeks) were compared with 176 normal birth weight children of similar maternal sociodemographic status, sex, and age. Behavior was assessed via the Child Symptom Inventory that includes both Symptom Severity Scores and scores meeting DSM-IV criteria for disorders. Results: ELBW compared with normal birth weight children had significantly higher mean Symptom Severity Scores for the inattentive, hyperactive, and combined types of attention-deficit hyperactivity disorder (all p < .001) as well as higher scores for Generalized Anxiety (p < .01) and Autistic (p < .001) and Aspergers (p < .01) disorders. When DSM-IV criteria were considered, ELBW children also had significantly higher rates of attention-deficit hyperactivity disorder of the inattentive (10% vs 3%, p < .01) and combined (5% vs 0.6%, p < .05) types. Conclusions: Attention-deficit hyperactivity disorder, mainly the inattentive type is prevalent among ELBW children. Our findings of an increase in symptoms pertaining to Autistic and Aspergers disorders at school age agree with recent reports of others during early childhood. Early identification and intervention for these problems might improve child functioning and ameliorate parent and child distress.

Learning Disabilities in Children with Very Low Birthweight Prevalence, Neuropsychological Correlates, and Educational Interventions

This study examined achievement, neuropsychological, and intervention outcomes at a mean age of 11 years in children with very low birthweight (VLBW, < 1,500 g) compared with a term-born control group. To assess the prevalence and correlates of specific learning disabilities (LD), the sample was limited to children without neurosensory disorders who had at least low average IQ. Participants included 31 children with < 750 g birthweight, 41 with 750—1,499 g birthweight, and 52 controls. The < 750 g group obtained lower scores in math, IQ, and perceptual—organizational skills than the term-born group. The < 750 g group also had higher rates of past and present LD than the controls. Despite these differences, the groups did not differ significantly in rates of special education or tutorial/remedial assistance. These findings suggest that children with extremely low birthweight without gross physical or intellectual impairments are at higher risk for LD and cognitive deficiencies than their term-born peers and that further efforts are needed to improve identification and treatment of these learning problems.

School-Age Consequences of Birth Weight Less Than 750 g: A Review and Update

Recent advances in perinatal care have led to the survival of increasing numbers of children born at the lower limits of viability. Children with very low birth weight (LBW; less than 1,500 g, 3 lb 5 oz) have been studied extensively. Findings document poorer outcomes relative to normal birth weight term-born controls in neurologic and health status, cognitive-neuropsychological skills, school performance, academic achievement, and behavior. This report reviews current knowledge regarding LBW children, with special emphasis on outcomes for children with birth weight less than 750 g (1 lb 10 oz). Results from an ongoing longitudinal study suggest a gradient of sequelae, with poorer outcomes in less than 750 g birth weight children compared to both 750 g to 1,499 g birth weight children and term-born controls. Children with less than 750 g birth weight fail to catch up with their peers over time and may even be at risk for age-related increases in sequelae. Outcomes are highly variable but related to neonatal medical complications of prematurity and social risk factors. Further research is needed to understand the etiology and neuropathological basis of sequelae, the long-term developmental implications of LBW, and treatment needs.